: rising sea levels. today, newyorkcitymayormichael bloomberg announced a new long-term initiative to protect the city from future natural disasters. he called for rebuilding vulnerable coastal areas, but dismissed again the idea of constructing a large sea-gate across the harbor. >> we're not going to abandon the waterfront. we're not going to abandon the rockaways or coney island or staten island's south shore. but we can't just rebuild what was there and hope for the best. we have to build smarter and stronger and more sustainably. >> woodruff: 350 miles south. the city of norfolk, virginia, is another coastal city vulnerable to sea level rise and extreme storms. but its mayor has said parts of his city might not be livable in the future. our producer, mike melia, traveled to norfolk recently to look at how it has been struggling with flooding and preparing for the next big storm. he worked with member station whro to bring us this report. it's part of our series-- working with public media partners across the country-- that we call "battleground dispatches." >> reporter: when r